fix(ai): replay refusals as text

packages/ai/src/protocols/open-responses.ts

@@ -254,7 +254,10 @@ export const Event = Schema.StructWithRest(
     type: Schema.String,
     delta: Schema.optional(Schema.String),
     text: Schema.optional(Schema.String),
+    refusal: Schema.optional(Schema.String),
     item_id: Schema.optional(Schema.String),
+    output_index: Schema.optional(Schema.Number),
+    content_index: Schema.optional(Schema.Number),
     summary_index: Schema.optional(Schema.Number),
     item: Schema.optional(StreamItem),
     response: Schema.optional(
@@ -688,6 +691,35 @@ const onOutputTextDone = (state: ParserState, event: Event, id: string): StepRes
   return [{ ...state, lifecycle: Lifecycle.textEnd(state.lifecycle, events, id) }, events]
 }
 
+const refusalID = (event: Event) => `refusal:${event.item_id}:${event.content_index}`
+
+const messageMetadata = (
+  state: ParserState,
+  itemID: string,
+  phase: MessagePhase | null | undefined = state.messagePhases[itemID],
+) => (phase === undefined ? undefined : providerMetadata(state, { phase }))
+
+const onRefusalDelta = (state: ParserState, event: Event): StepResult => {
+  if (!event.item_id || !event.delta) return [state, NO_EVENTS]
+  const events: LLMEvent[] = []
+  const id = refusalID(event)
+  const lifecycle = Lifecycle.textStart(state.lifecycle, events, id, messageMetadata(state, event.item_id))
+  return [{ ...state, lifecycle: Lifecycle.textDelta(lifecycle, events, id, event.delta) }, events]
+}
+
+const onRefusalDone = (state: ParserState, event: Event): StepResult => {
+  if (!event.item_id) return [state, NO_EVENTS]
+  const events: LLMEvent[] = []
+  const id = refusalID(event)
+  const metadata = messageMetadata(state, event.item_id)
+  const started =
+    state.lifecycle.text.has(id) || event.refusal === undefined
+      ? state.lifecycle
+      : Lifecycle.textDelta(Lifecycle.textStart(state.lifecycle, events, id, metadata), events, id, event.refusal)
+  if (state.messageItems.has(event.item_id)) return [{ ...state, lifecycle: started }, events]
+  return [{ ...state, lifecycle: Lifecycle.textEnd(started, events, id, metadata) }, events]
+}
+
 export const onReasoningDelta = (state: ParserState, event: Event, itemID: string): StepResult => {
   if (!event.delta) return [state, NO_EVENTS]
   const events: LLMEvent[] = []
@@ -890,21 +922,24 @@ const onOutputItemDone = Effect.fn("OpenResponses.onOutputItemDone")(function* (
   if (!item) return [state, NO_EVENTS] satisfies StepResult
 
   if (item.type === "message" && item.id) {
+    const itemID = item.id
     const itemPhase = state.messagePhase(item.phase)
-    const phase = itemPhase === undefined ? state.messagePhases[item.id] : itemPhase
+    const phase = itemPhase === undefined ? state.messagePhases[itemID] : itemPhase
     const events: LLMEvent[] = []
+    const metadata = phase === undefined ? undefined : providerMetadata(state, { phase })
+    const lifecycle = Array.from(state.lifecycle.text)
+      .filter((id) => id.startsWith(`refusal:${itemID}:`))
+      .reduce(
+        (lifecycle, id) => Lifecycle.textEnd(lifecycle, events, id, messageMetadata(state, itemID, phase)),
+        Lifecycle.textEnd(state.lifecycle, events, itemID, metadata),
+      )
     const messageItems = new Set(state.messageItems)
-    messageItems.delete(item.id)
-    const { [item.id]: _phase, ...messagePhases } = state.messagePhases
+    messageItems.delete(itemID)
+    const { [itemID]: _phase, ...messagePhases } = state.messagePhases
     return [
       {
         ...state,
-        lifecycle: Lifecycle.textEnd(
-          state.lifecycle,
-          events,
-          item.id,
-          phase === undefined ? undefined : providerMetadata(state, { phase }),
-        ),
+        lifecycle,
         messageItems,
         messagePhases,
       },
@@ -1026,6 +1061,20 @@ export const step = (state: ParserState, event: Event) => {
         : onOutputTextDone(state, event, event.item_id),
     )
   }
+  if (event.type === "response.refusal.delta" || event.type === "response.refusal.done") {
+    if (!event.item_id) return ProviderShared.eventError(state.id, `${event.type} is missing item_id`)
+    if (event.output_index === undefined)
+      return ProviderShared.eventError(state.id, `${event.type} is missing output_index`)
+    if (event.content_index === undefined)
+      return ProviderShared.eventError(state.id, `${event.type} is missing content_index`)
+    if (event.type === "response.refusal.delta" && event.delta === undefined)
+      return ProviderShared.eventError(state.id, `${event.type} is missing delta`)
+    if (event.type === "response.refusal.done" && event.refusal === undefined)
+      return ProviderShared.eventError(state.id, `${event.type} is missing refusal`)
+    return Effect.succeed(
+      event.type === "response.refusal.delta" ? onRefusalDelta(state, event) : onRefusalDone(state, event),
+    )
+  }
   if (event.type === "response.reasoning.delta" || event.type === "response.reasoning_summary_text.delta") {
     if (!event.item_id) return ProviderShared.eventError(state.id, `${event.type} is missing item_id`)
     return Effect.succeed(onReasoningDelta(state, event, event.item_id))

packages/ai/src/protocols/openai-chat.ts

@@ -28,7 +28,7 @@ import { ToolSchemaProjection } from "./utils/tool-schema.js"
 import { ToolStream } from "./utils/tool-stream.js"
 
 const ADAPTER = "openai-chat"
-const RESERVED_REASONING_FIELDS = new Set(["role", "content", "tool_calls"])
+const RESERVED_REASONING_FIELDS = new Set(["role", "content", "refusal", "tool_calls"])
 export const DEFAULT_BASE_URL = "https://api.openai.com/v1"
 export const PATH = "/chat/completions"
 
@@ -194,6 +194,7 @@ type OpenAIChatToolCallDelta = Schema.Schema.Type<typeof OpenAIChatToolCallDelta
 const OpenAIChatDelta = Schema.StructWithRest(
   Schema.Struct({
     content: optionalNull(Schema.String),
+    refusal: optionalNull(Schema.String),
     reasoning_content: optionalNull(Schema.String),
     reasoning: optionalNull(Schema.String),
     reasoning_text: optionalNull(Schema.String),
@@ -709,6 +710,7 @@ const step = (state: ParserState, event: OpenAIChatEvent) =>
     const reasoning = reasoningDelta(delta, state.reasoningField)
     const hasLateContent =
       Boolean(delta?.content) ||
+      Boolean(delta?.refusal) ||
       reasoning !== undefined ||
       (Array.isArray(delta?.reasoning_details) && delta.reasoning_details.length > 0) ||
       toolDeltas.some((tool) => Boolean(tool.id) || Boolean(tool.function?.name) || Boolean(tool.function?.arguments))
@@ -728,7 +730,7 @@ const step = (state: ParserState, event: OpenAIChatEvent) =>
     else if (
       reasoningDetailsObserved &&
       !lifecycle.reasoning.has("reasoning-0") &&
-      (Boolean(delta?.content) || toolDeltas.length > 0)
+      (Boolean(delta?.content) || Boolean(delta?.refusal) || toolDeltas.length > 0)
     )
       lifecycle = Lifecycle.reasoningStart(lifecycle, events, "reasoning-0", deltaMetadata)
     const reasoningEmitted = state.reasoningEmitted || lifecycle.reasoning.has("reasoning-0")
@@ -743,6 +745,16 @@ const step = (state: ParserState, event: OpenAIChatEvent) =>
       lifecycle = Lifecycle.textDelta(lifecycle, events, "text-0", delta.content)
     }
 
+    if (delta?.refusal) {
+      lifecycle = Lifecycle.reasoningEnd(
+        lifecycle,
+        events,
+        "reasoning-0",
+        reasoningMetadata(reasoningField, reasoningDetailsObserved ? state.reasoningDetails : undefined),
+      )
+      lifecycle = Lifecycle.textDelta(lifecycle, events, "text-0", delta.refusal)
+    }
+
     // Compatible providers may omit indexes. Prefer durable identity, then use
     // batch position for parallel deltas or the latest call for sparse chunks.
     for (const [position, tool] of toolDeltas.entries()) {

packages/ai/test/provider/openai-chat.test.ts

@@ -664,6 +664,74 @@ describe("OpenAI Chat route", () => {
     }),
   )
 
+  it.effect("preserves streamed refusals as ordinary assistant text", () =>
+    Effect.gen(function* () {
+      const response = yield* LLMClient.generate(request).pipe(
+        Effect.provide(
+          fixedResponse(
+            sseEvents(
+              deltaChunk({ role: "assistant", refusal: "I can't" }),
+              deltaChunk({ refusal: " help with that." }),
+              deltaChunk({}, "stop"),
+            ),
+          ),
+        ),
+      )
+
+      expect(response.text).toBe("I can't help with that.")
+      expect(response.finishReason).toEqual({ normalized: "stop", raw: "stop" })
+      expect(response.message.content).toEqual([{ type: "text", text: "I can't help with that." }])
+
+      const replay = yield* compileRequest(LLM.request({ model, messages: [response.message] }))
+      expect(replay.body.messages).toEqual([{ role: "assistant", content: "I can't help with that." }])
+    }),
+  )
+
+  it.effect("orders metadata-only reasoning before refusal output", () =>
+    Effect.gen(function* () {
+      const response = yield* LLMClient.generate(request).pipe(
+        Effect.provide(
+          fixedResponse(
+            sseEvents(
+              { choices: [{ delta: { reasoning_details: [] } }] },
+              deltaChunk({ refusal: "I can't help with that." }),
+              deltaChunk({}, "stop"),
+            ),
+          ),
+        ),
+      )
+
+      expect(response.message.content).toEqual([
+        { type: "reasoning", text: "", providerMetadata: { openai: { reasoningDetails: [] } } },
+        {
+          type: "text",
+          text: "I can't help with that.",
+        },
+      ])
+    }),
+  )
+
+  it.effect("joins content and refusal deltas into ordinary assistant text", () =>
+    Effect.gen(function* () {
+      const response = yield* LLMClient.generate(request).pipe(
+        Effect.provide(
+          fixedResponse(
+            sseEvents(
+              deltaChunk({ refusal: "No." }),
+              deltaChunk({ content: " Alternative." }),
+              deltaChunk({ refusal: " Still no." }),
+              deltaChunk({}, "stop"),
+            ),
+          ),
+        ),
+      )
+
+      expect(response.text).toBe("No. Alternative. Still no.")
+      expect(response.events.filter(LLMEvent.is.textStart).map((event) => event.id)).toEqual(["text-0"])
+      expect(response.events.filter(LLMEvent.is.textEnd).map((event) => event.id)).toEqual(["text-0"])
+    }),
+  )
+
   it.effect("parses and replays OpenAI-compatible reasoning fields", () =>
     Effect.gen(function* () {
       const fields = ["reasoning_content", "reasoning", "reasoning_text"] as const

packages/ai/test/provider/openai-compatible-responses.test.ts

@@ -118,6 +118,53 @@ describe("Open Responses-compatible route", () => {
     }),
   )
 
+  it.effect("preserves standard refusal content as ordinary assistant text", () =>
+    Effect.gen(function* () {
+      const model = configure({
+        apiKey: "test-key",
+        baseURL: "https://responses.example.test/v1",
+        provider: "example",
+      }).model("example-model")
+      const response = yield* LLMClient.generate(LLM.request({ model, prompt: "Unsafe request" })).pipe(
+        Effect.provide(
+          fixedResponse(
+            sseEvents(
+              {
+                type: "response.output_item.added",
+                output_index: 0,
+                item: { type: "message", id: "msg_refusal", content: [] },
+              },
+              {
+                type: "response.refusal.done",
+                item_id: "msg_refusal",
+                output_index: 0,
+                content_index: 0,
+                refusal: "I can't help with that.",
+              },
+              {
+                type: "response.output_item.done",
+                output_index: 0,
+                item: {
+                  type: "message",
+                  id: "msg_refusal",
+                  content: [{ type: "refusal", refusal: "I can't help with that." }],
+                },
+              },
+              { type: "response.completed", response: { id: "resp_1" } },
+            ),
+          ),
+        ),
+      )
+
+      expect(response.message.content).toEqual([{ type: "text", text: "I can't help with that." }])
+
+      const prepared = yield* compileRequest(LLM.request({ model, messages: [response.message] }))
+      expect(prepared.body.input).toEqual([
+        { role: "assistant", content: [{ type: "output_text", text: "I can't help with that." }] },
+      ])
+    }),
+  )
+
   it.effect("reads standard options from the Open Responses namespace", () =>
     Effect.gen(function* () {
       const model = configure({

packages/ai/test/provider/openai-responses.test.ts

@@ -1481,6 +1481,108 @@ describe("OpenAI Responses route", () => {
     }),
   )
 
+  it.effect("preserves standard refusal content as ordinary assistant text", () =>
+    Effect.gen(function* () {
+      const response = yield* LLMClient.generate(request).pipe(
+        Effect.provide(
+          fixedResponse(
+            sseEvents(
+              {
+                type: "response.output_item.added",
+                output_index: 0,
+                item: { type: "message", id: "msg_refusal", content: [] },
+              },
+              {
+                type: "response.content_part.added",
+                item_id: "msg_refusal",
+                output_index: 0,
+                content_index: 0,
+                part: { type: "refusal", refusal: "" },
+              },
+              {
+                type: "response.refusal.delta",
+                item_id: "msg_refusal",
+                output_index: 0,
+                content_index: 0,
+                delta: "I can't",
+              },
+              {
+                type: "response.refusal.delta",
+                item_id: "msg_refusal",
+                output_index: 0,
+                content_index: 0,
+                delta: " help with that.",
+              },
+              {
+                type: "response.refusal.done",
+                item_id: "msg_refusal",
+                output_index: 0,
+                content_index: 0,
+                refusal: "I can't help with that.",
+              },
+              {
+                type: "response.content_part.done",
+                item_id: "msg_refusal",
+                output_index: 0,
+                content_index: 0,
+                part: { type: "refusal", refusal: "I can't help with that." },
+              },
+              {
+                type: "response.output_item.done",
+                output_index: 0,
+                item: {
+                  type: "message",
+                  id: "msg_refusal",
+                  phase: "final_answer",
+                  content: [{ type: "refusal", refusal: "I can't help with that." }],
+                },
+              },
+              { type: "response.completed", response: { id: "resp_1" } },
+            ),
+          ),
+        ),
+      )
+
+      expect(response.text).toBe("I can't help with that.")
+      expect(response.finishReason).toEqual({ normalized: "stop", raw: undefined })
+      expect(response.message.content).toEqual([
+        {
+          type: "text",
+          text: "I can't help with that.",
+          providerMetadata: { openai: { phase: "final_answer" } },
+        },
+      ])
+
+      const prepared = yield* compileRequest(LLM.request({ model, messages: [response.message] }))
+      expect(prepared.body.input).toEqual([
+        {
+          role: "assistant",
+          content: [{ type: "output_text", text: "I can't help with that." }],
+          phase: "final_answer",
+        },
+      ])
+    }),
+  )
+
+  it.effect("rejects refusal events without standard content coordinates", () =>
+    Effect.gen(function* () {
+      const events = [
+        { type: "response.refusal.delta", output_index: 0, content_index: 0, delta: "missing item" },
+        { type: "response.refusal.delta", item_id: "msg_1", content_index: 0, delta: "missing output" },
+        { type: "response.refusal.delta", item_id: "msg_1", output_index: 0, delta: "missing content" },
+        { type: "response.refusal.delta", item_id: "msg_1", output_index: 0, content_index: 0 },
+        { type: "response.refusal.done", item_id: "msg_1", output_index: 0, content_index: 0 },
+      ]
+      for (const event of events) {
+        const error = yield* LLMClient.generate(request).pipe(
+          Effect.provide(fixedResponse(sseEvents(event))),
+          Effect.flip,
+        )
+        expect(error.reason._tag).toBe("InvalidProviderOutput")
+      }
+    }),
+  )
+
   it.effect("preserves and replays assistant message phases", () =>
     Effect.gen(function* () {
       const response = yield* LLMClient.generate(request).pipe(